Mercurial > hg > nginx
view src/http/ngx_http_write_filter_module.c @ 7678:bffcc5af1d72
Upstream: drop extra data sent by upstream.
Previous behaviour was to pass everything to the client, but this
seems to be suboptimal and causes issues (ticket #1695). Fix is to
drop extra data instead, as it naturally happens in most clients.
This change covers generic buffered and unbuffered filters as used
in the scgi and uwsgi modules. Appropriate input filter init
handlers are provided by the scgi and uwsgi modules to set corresponding
lengths.
Note that for responses to HEAD requests there is an exception:
we do allow any response length. This is because responses to HEAD
requests might be actual full responses, and it is up to nginx
to remove the response body. If caching is enabled, only full
responses matching the Content-Length header will be cached
(see b779728b180c).
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 06 Jul 2020 18:36:22 +0300 |
parents | c19ca381b2e6 |
children | 61e9c078ee3d 94daa42ff5ce |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> static ngx_int_t ngx_http_write_filter_init(ngx_conf_t *cf); static ngx_http_module_t ngx_http_write_filter_module_ctx = { NULL, /* preconfiguration */ ngx_http_write_filter_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ NULL, /* create location configuration */ NULL, /* merge location configuration */ }; ngx_module_t ngx_http_write_filter_module = { NGX_MODULE_V1, &ngx_http_write_filter_module_ctx, /* module context */ NULL, /* module directives */ NGX_HTTP_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; ngx_int_t ngx_http_write_filter(ngx_http_request_t *r, ngx_chain_t *in) { off_t size, sent, nsent, limit; ngx_uint_t last, flush, sync; ngx_msec_t delay; ngx_chain_t *cl, *ln, **ll, *chain; ngx_connection_t *c; ngx_http_core_loc_conf_t *clcf; c = r->connection; if (c->error) { return NGX_ERROR; } size = 0; flush = 0; sync = 0; last = 0; ll = &r->out; /* find the size, the flush point and the last link of the saved chain */ for (cl = r->out; cl; cl = cl->next) { ll = &cl->next; ngx_log_debug7(NGX_LOG_DEBUG_EVENT, c->log, 0, "write old buf t:%d f:%d %p, pos %p, size: %z " "file: %O, size: %O", cl->buf->temporary, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last - cl->buf->pos, cl->buf->file_pos, cl->buf->file_last - cl->buf->file_pos); if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "zero size buf in writer " "t:%d r:%d f:%d %p %p-%p %p %O-%O", cl->buf->temporary, cl->buf->recycled, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last, cl->buf->file, cl->buf->file_pos, cl->buf->file_last); ngx_debug_point(); return NGX_ERROR; } if (ngx_buf_size(cl->buf) < 0) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "negative size buf in writer " "t:%d r:%d f:%d %p %p-%p %p %O-%O", cl->buf->temporary, cl->buf->recycled, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last, cl->buf->file, cl->buf->file_pos, cl->buf->file_last); ngx_debug_point(); return NGX_ERROR; } size += ngx_buf_size(cl->buf); if (cl->buf->flush || cl->buf->recycled) { flush = 1; } if (cl->buf->sync) { sync = 1; } if (cl->buf->last_buf) { last = 1; } } /* add the new chain to the existent one */ for (ln = in; ln; ln = ln->next) { cl = ngx_alloc_chain_link(r->pool); if (cl == NULL) { return NGX_ERROR; } cl->buf = ln->buf; *ll = cl; ll = &cl->next; ngx_log_debug7(NGX_LOG_DEBUG_EVENT, c->log, 0, "write new buf t:%d f:%d %p, pos %p, size: %z " "file: %O, size: %O", cl->buf->temporary, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last - cl->buf->pos, cl->buf->file_pos, cl->buf->file_last - cl->buf->file_pos); if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "zero size buf in writer " "t:%d r:%d f:%d %p %p-%p %p %O-%O", cl->buf->temporary, cl->buf->recycled, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last, cl->buf->file, cl->buf->file_pos, cl->buf->file_last); ngx_debug_point(); return NGX_ERROR; } if (ngx_buf_size(cl->buf) < 0) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "negative size buf in writer " "t:%d r:%d f:%d %p %p-%p %p %O-%O", cl->buf->temporary, cl->buf->recycled, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last, cl->buf->file, cl->buf->file_pos, cl->buf->file_last); ngx_debug_point(); return NGX_ERROR; } size += ngx_buf_size(cl->buf); if (cl->buf->flush || cl->buf->recycled) { flush = 1; } if (cl->buf->sync) { sync = 1; } if (cl->buf->last_buf) { last = 1; } } *ll = NULL; ngx_log_debug3(NGX_LOG_DEBUG_HTTP, c->log, 0, "http write filter: l:%ui f:%ui s:%O", last, flush, size); clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); /* * avoid the output if there are no last buf, no flush point, * there are the incoming bufs and the size of all bufs * is smaller than "postpone_output" directive */ if (!last && !flush && in && size < (off_t) clcf->postpone_output) { return NGX_OK; } if (c->write->delayed) { c->buffered |= NGX_HTTP_WRITE_BUFFERED; return NGX_AGAIN; } if (size == 0 && !(c->buffered & NGX_LOWLEVEL_BUFFERED) && !(last && c->need_last_buf)) { if (last || flush || sync) { for (cl = r->out; cl; /* void */) { ln = cl; cl = cl->next; ngx_free_chain(r->pool, ln); } r->out = NULL; c->buffered &= ~NGX_HTTP_WRITE_BUFFERED; return NGX_OK; } ngx_log_error(NGX_LOG_ALERT, c->log, 0, "the http output chain is empty"); ngx_debug_point(); return NGX_ERROR; } if (!r->limit_rate_set) { r->limit_rate = ngx_http_complex_value_size(r, clcf->limit_rate, 0); r->limit_rate_set = 1; } if (r->limit_rate) { if (!r->limit_rate_after_set) { r->limit_rate_after = ngx_http_complex_value_size(r, clcf->limit_rate_after, 0); r->limit_rate_after_set = 1; } limit = (off_t) r->limit_rate * (ngx_time() - r->start_sec + 1) - (c->sent - r->limit_rate_after); if (limit <= 0) { c->write->delayed = 1; delay = (ngx_msec_t) (- limit * 1000 / r->limit_rate + 1); ngx_add_timer(c->write, delay); c->buffered |= NGX_HTTP_WRITE_BUFFERED; return NGX_AGAIN; } if (clcf->sendfile_max_chunk && (off_t) clcf->sendfile_max_chunk < limit) { limit = clcf->sendfile_max_chunk; } } else { limit = clcf->sendfile_max_chunk; } sent = c->sent; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0, "http write filter limit %O", limit); chain = c->send_chain(c, r->out, limit); ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0, "http write filter %p", chain); if (chain == NGX_CHAIN_ERROR) { c->error = 1; return NGX_ERROR; } if (r->limit_rate) { nsent = c->sent; if (r->limit_rate_after) { sent -= r->limit_rate_after; if (sent < 0) { sent = 0; } nsent -= r->limit_rate_after; if (nsent < 0) { nsent = 0; } } delay = (ngx_msec_t) ((nsent - sent) * 1000 / r->limit_rate); if (delay > 0) { limit = 0; c->write->delayed = 1; ngx_add_timer(c->write, delay); } } if (limit && c->write->ready && c->sent - sent >= limit - (off_t) (2 * ngx_pagesize)) { c->write->delayed = 1; ngx_add_timer(c->write, 1); } for (cl = r->out; cl && cl != chain; /* void */) { ln = cl; cl = cl->next; ngx_free_chain(r->pool, ln); } r->out = chain; if (chain) { c->buffered |= NGX_HTTP_WRITE_BUFFERED; return NGX_AGAIN; } c->buffered &= ~NGX_HTTP_WRITE_BUFFERED; if ((c->buffered & NGX_LOWLEVEL_BUFFERED) && r->postponed == NULL) { return NGX_AGAIN; } return NGX_OK; } static ngx_int_t ngx_http_write_filter_init(ngx_conf_t *cf) { ngx_http_top_body_filter = ngx_http_write_filter; return NGX_OK; }